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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 68 · 40 questions
TalentJR

Robot tip (Teeth × turns): Teeth passing = driver teeth × driver turns. Driven turns = teeth passing ÷ driven teeth. Gear ratio = driven teeth ÷ driver teeth (a ratio of 3 means 3 times slower).

NameDateTime takenScore ___ / 40
  1. 1.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) zero (b) never important (c) small (fast, weak) (d) big (slow and strong)
  2. 2.🔢 Gear ratio = driven teeth ÷ … (a) driver teeth (b) wheel size (c) motor volts (d) number of gears
  3. 3.⚙️ A 12-tooth gear drives a 36-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  4. 4.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times louder (c) 3 times slower (d) 3 times faster
  5. 5.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  6. 6.⚙️ A 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  7. 7.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  8. 8.⚙️ A motor makes 240 turns a minute with a 10-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  9. 9.⚙️ A 12-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  10. 10.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  11. 11.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  12. 12.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  13. 13.⚙️ A motor makes 120 turns a minute with a 10-tooth gear on it. That gear drives a 30-tooth gear. How many turns a minute does the 30-tooth gear make?
  14. 14.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  15. 15.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  16. 16.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  17. 17.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  18. 18.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  19. 19.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  20. 20.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  21. 21.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 45 times. How many times does the driven gear turn?
  22. 22.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  23. 23.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  24. 24.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 36 times. How many times does the driven gear turn?
  25. 25.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  26. 26.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  28. 28.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  29. 29.⚙️ A motor makes 20 turns a minute with a 12-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  30. 30.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  31. 31.⚙️ An 8-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  32. 32.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  33. 33.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  34. 34.⚙️ A motor makes 210 turns a minute with an 8-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  35. 35.⚙️ A motor makes 450 turns a minute with a 15-tooth gear on it. That gear drives a 75-tooth gear. How many turns a minute does the 75-tooth gear make?
  36. 36.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  37. 37.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  38. 38.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 35 times. How many times does the driven gear turn?
  39. 39.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  40. 40.⚙️ A motor makes 500 turns a minute with a 15-tooth gear on it. That gear drives a 75-tooth gear. How many turns a minute does the 75-tooth gear make?

Answer key

  1. big (slow and strong)
  2. driver teeth
  3. 3
  4. 3 times slower
  5. 20
  6. 40
  7. 18
  8. 60
  9. 5
  10. 8
  11. 6
  12. 8
  13. 40
  14. 27
  15. 30
  16. 15
  17. 2
  18. 24
  19. 2
  20. 24
  21. 9
  22. 18
  23. 8
  24. 9
  25. 24
  26. 48
  27. 4
  28. 10
  29. 10
  30. 40
  31. 3
  32. 4
  33. 2
  34. 70
  35. 90
  36. 20
  37. 18
  38. 7
  39. 30
  40. 100

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